My apologies. What I wrote was ambiguous. Obviously I know that penal satisfaction is common. What surprised me was that *opposition* to it was so widespread that a PCUSA committee would consider it obviously a problem. Based on an account of the discussion, the argument was not over whether it was correct, but whether it could be tolerated, given that some churches clearly wanted it. Their decision was no.
The Confession of 1967 lists it as one of the ways Scripture talks about the atonement. The 1983/5 documents don't give any theory of the atonement. However there are certainly many Presbyterians who accept it.
I see where many Scripture passages can be interpreted as consistent with it. I don't see any that mandate it. We've been through these discussions in Soteriology, and the citations all involve some level of eisegesis. Again there's nothing in Scripture that would rule it out. I can see it as a possible understanding of the evidence. I just don't see it as the only or even most likely. Certainly the Reformed view is preferable to Anselm's.
My objection is mot to substitution, to our sin deserving punishment, to Christ suffering on our behalf, or to the exchange described in Rom 6. It is to the concept that God can't forgive us without punishing us. That is contrary to Jesus' teaching, and I'm pretty sure also to Paul's. As I understand Paul, Jesus replaces the legal system under which there was nothing better to do with sin than to punish it, with an atonement that actually takes it away, by Christ taking it and defeating it.
I agree with most of the discussion in Institutes 2.16, however in 2.16.5 Calvin's reference to the curse of the Law seems to reflect his understanding of Gal 3:13, which fails to take into account the law/grace issue with which it is primarily dealing. Calvin treats the passage as if the law's demand for punishment is a legitimate one which we have to satisfy, and can do so only through Christ. But Paul's whole point is that the legal system is not what we depend upon for salvation, however much it may have other uses. Christ takes on for us the character of a sinner under the law, as Calvin notes, but he does so that by his death and resurrection he can abolish the curse of the Law. Not by satisfying God's demand for punishment, but by establishing a better way.
Perhaps I should call this penal substitution. After all Christ takes our sins, which under the law we would be liable to punishment for, and by dying for them wipes out our punishment. It's just that I don't see in Paul that God actually punishing him for our sins. Rather his death abolishes both our sins (Rom 6) and the requirement for punishment (Gal 3:13), nailing the Law to the cross, as Calvin says.
Paul's actual discussion of the atonement in Rom 6 does not say that Christ satisfies God's need to punish someone. For him it is axiomatic that death ends slavery to sin (Rom 6:7). Commentators have suggested several sources for that idea, but none is obviously best, and none is particularly based on punishment (not even in Calvin's commentary on Rom 6:7). Because he has taken on our sin, his death ends slavery to sin not for himself, but for us. And the same union that let him take our sin gives us the new life of his resurrection.
This is vicarious sacrifice, but I don't think it's penal substitution. As calvin notes in 2:16:2-4, God is angry at sin. However in 2:16:3 he says that God's wrath applies only to our sin, not ourselves. He explains the Biblical language speaking of God being angry at us as non-literal ("accommodation"). He loves us, and in fact receives us before Jesus' death. However he can't receive us fully as long as we are sinful, and thus he uses the atonement to deal with our sin. The point here isn't that he has to punish us, but that he has to deal with our sin. In 2:16:5-7, Jesus takes on our sin in order to defeat it, and in the exchange, he obedience becomes ours. However as noted above, I don't entirely agree with his explanation.